This invention relates to a foldable or collapsible ladder adapted for use on homes, apartments, schools, hospitals, office buildings and any other structures where people are likely to be more than one floor above ground level. More particularly, this invention relates to a lightweight collapsible ladder having an inner upright secured to the wall of the structure and a parallel outer upright connected to the inner upright by pivotally mounted rungs, and movable from a closed position, in which the outer upright abuts the inner upright, downwardly and outwardly through an arc to an open position, in which the outer upright is spaced from the inner upright and the connecting rungs are horizontal. Still more particularly, this invention relates to a releasable locking means holding the ladder in a closed position and releasable by the hand or foot of the user to allow the outer upright to swing through an arc under the influence of gravity until the ladder is in the open position. Still more particularly, this invention relates to a lightweight collapsible ladder which is adapted to be secured in a series to the wall of a structure so that a user may open each ladder in sequence and descend them, one after the other, until he reaches safety.
It is an overall object of this invention to provide a lightweight collapsible ladder which will provide easy, safe and swift exit from a structure in case of fire or other emergency. It is a further object of the invention to provide a collapsible ladder which can be mounted on either the left or right side of a window or other structure opening. It is another object of the invention to provide an escape ladder which is closed during periods of nonuse to prevent unauthorized use and to prevent burglary. Still another object of the invention is to provide a ladder which requires little space and is aesthetically pleasing during periods of nonuse. It is a still further object of the invention to provide a ladder which will be very durable and maintenance free. It is also an object of the invention to provide a ladder which is adapted to be used in a vertically arranged series of ladders to permit escape from a structure of any height.